Conventionally, a hands-free apparatus that communicates with a portable communication device such as a cellular phone or the like for enabling a hands-free call is disclosed in, for example, Japanese patent document JP-A-2005-286827 (This document is published in U.S. under a publication No. US 2007-0281735). A user of the hands-free apparatus can speak to a call partner without picking up the portable communication device through the hands-free apparatus.
When a call from a third person is incoming to an already busy line of a fixed telephone or a cellular phone, the user of the busy line can switch a current call to the incoming call from the third person by holding the current call with Catch-Phone function (Registered trademark in Japan. Equivalent to call-waiting). These telephone terminals switch the telephone number or the name of the call partner displayed on a display unit when the current call is switched to the call from the third person.
However, when the user performs an operation on the display unit of the hands-free apparatus for switching the call partners by using the call-waiting, the cellular phone does not sends call partner information to the hands-free apparatus even after switching the call partners upon having a call partner switching instruction sent from the hands-free apparatus by utilizing the call-waiting, thereby leaving a chance of displaying a false call partner phone number or name after switching the call partners.